Liquid level indicator



Feb. 2, 1937. c. L. Howss 2,069,312.

LIQUID LEVEL INDICATOR Filed May 15, 1933 HORMAZ 2 24 FIG. I

INVEN R ATTORNEY Patented Feb. 2, 1937 UNITED STATES PATENT OFFICELIQUID LEVEL INDICATOR;

Application May 15, 1933, Serial No. 671,079

13 Claims.

The invention is directed to an improvement in liquid level indicatorsparticularly of the type in which an alarm is sounded to indicatechanges in I water level in a container, such, for example, as a boilerdrum. More particularly, the invention is directed to an improvement inthat form of alarm mechanism employing the weight displacementprinciple.

In high and low liquid; alarm apparatus employing this principle, asheretofore constructed, the entire system of weights and supportinglevers has been mounted inside the column, or the like, connected by theusual means to the boiler drum or container. As heretofore constructed,the entire system of weights has been suspended from and supported bythe system of levers used to actuate the valve controlling the supply ofsteam to the alarm device, such as the whistle. Even though the systemof levers be supported on knife 20' edges due to the fact that they havehad to carry the weight of the displacement members, the action of theaffair has been sluggish and has been subject to certain very definitelimitations. Where the weights are carried by such lever supports, themechanism is somewhat dependent in its action upon the temperature ofthe water in the column. Moreover, at pressures higher than 600 lbs.approximately, the density of the water decreases to such a point thatweights of excessive size are employed. This can only be accomplished byincreasing the vertical dimension of the weights in order to procure theadditional force required to operate the leverage system against .thehigher pressures and particularly to open the valve against such higherpressure. This additional weight causes increased friction which furtherincreases the sluggishness of operation of the device employing theweight displacement principle. In fact, practice has indicated thatapproximately 600 lbs. is the limit where apparatus of this type may besatisfactorily employed.

In the present invention this objection is overcome by providing anindependent support for the weight system so that the system of leversemployed has only to actuate the valve controlling the flow of steam orthe like to. the alarm device. A novel type of leverage mechanism isused as will be hereinafter described. Furthermore, other features andadvantages of the invention will be noted as the description proceeds,reference being had to the accompanying drawing wherein like parts aredesignated by like reference characters throughout and wherein:

Figure 1 is an end elevation of the boiler drum to which is attached aconventional water column embodying the invention;

Figure 2 is a view principally in section but partly in elevation andwith someof the parts broken away, the view being taken longitudinallythrough a water column embodying the invention; and

Figure 3 is an elevation partly broken away substantially along the line33 of Figure 2.

Referring, first of all, to Figure 1, the boiler I drum is designated atI; 2 represents the conventional column connected to the boiler drumabove and below the water level therein through connections 4 and 3,threadably engaging the column 2 at 5 and 6 respectively. This view alsoindicates the normal water level to be maintained in the drum andfurther indicates the high and low limits of water level;

Referring now to Figure 2, the column 2 is threadably engaged at its topby the flange I the open top of the-column 2 is closed by cover 8through a suitable gasketed joint 9, bolts I0 and nuts II being employedto fix the cover 8 to the flange "I.

In a gasketed recess I3 in the top of the cover 8 is mounted the memberI2 to receive the spring mechanism to be hereinafter described. Thehollow member I2 is provided as shown in Figure 3 with bosses I4,receiving studs I4 which, in conjunction with nuts I5, fix the body I2to the cover 8.

Mounted on top of the hollow member I2 is the cap I6 providedwith thebosses I'l. These are engaged also by studs I4 and nuts I8 are employedto force the cap member I6 into a fluid tight engagement with the hollowmember I2.

On the rod located interiorly of the column 2, are mounted the weights2i and 22. Nuts 24 and 23 engaging threaded portions of the rod 20 serveto adjustably fix the weight 2I in position. Similarly the lower portionof rod 20 threadably engages weight 22 and in conjunction with nut 25adjustably fixes the weight 22 in positionon rod 20. The feature ofadjustability allows the weights to be positioned at the proper point onrod 2|! to actuate the alarm device at the desired limits of high andlow water level.

Fixed to rod 20 at 26 is an eye-bolt 21 extending upwardly through anopening in cover 8. To the upper portion of this eye-bolt 21 is fixed aspring 28. To the upper portion of this spring is fixed a secondeye-bolt 29 threadably engaged in the top of the hollow member I2.Adjusting nut 30 is provided to engage eye-bolt 29 and to adjust thetension of spring 28 in dependence her l2 and the upon the amount ofweight suspended therefrom.

A suitable opening in cover 8 is provided to receive rod 21, this beingmade as small as practical in order to minimize the amount of steamwhich will pass into the upper hollow chamber l2. It is desirable tomaintain spring 28 located in this chamber at as low a temperature aspossible. To aid in this, the insulating sheet 84 may be provided at thebottom of chamchamber |2 might, if desired, be provided with radiatingfins I2 or the like to dissipate the heat therefrom and maintain thesame at as low a temperature as possible.

The composition of the spring 28 is of particular importance inconnection with this invention. This is preferably made of an alloy ofberyllium and copper in which the beryllium is present in the amount of2 to 2% percent and the balance is copper. A spring constructed of thismaterial is non-corrodible and is extremely valuable in springcharacteristics. In particular, it has an unusually high fatigue limitand, in general, the material has properties which admirably fit it forthe present application.

The adjustable spring support just described obviously carries theweight of the rod 20. plus the displacement weights 2| and 22. Theseweights are, therefore, not carried by the system of levers used toactuate the valve controlling to the alarm device. I An advantageousconstruction is thus provided which is very much more active and surerin operation than is the conventional weight displacement high and lowliquid alarm mechanism in which the weights are suspended from the valveoperating leverage system.

The upper portion of rod 28 is provided with a slot as indicated brokenaway in Figure 2. Through the slotted portion of the rod are mounted thepins 3| between which is loosely fitted the lever 32. This lever, inturn, is pivotally supported at 33 from bracket 88 fixed to the underside of cover I. Projections 88 on lever 35 are adapted to engage theupper surface of lever 32 and to be actuated thereby in a manner to be,hereinafter, described. lever 38 is pivotally supported at 38 frombracket 31, also fixed to the under side of cover 8. To the extremerighthand end of lever 28 is pivotally fixed valve stem 40. This valvestem terminates in an upper cone shaped valve member and is providedwith the spiders 8| to guide the valve stem movement in an openingformed in member 48 screwed into cover 8. This opening is furtherprovided at its upper extremity with the tapered seat portion 82. Fixedto the member is the alarm device 43 which may be a whistle ofconventional design.

The normal water level is indicated in Figure 2 and will occupy aposition between the top of weight 22 and the bottom of weight 2|. Withwater in the column at such normal level, spring 28, through adjustingscrew 38' is so regulated that valve 48' will engage seat 42 and nosteam from the upper space of the column will be passa ing to the alarmdevice tion of the apparatus, not be sounded.

If, in operation, the water level falls, weights 22 and 2| will movedownwardly carrying with them lever 82. This, in turn, will actuate'theleft-hand boss 38 on rod 38, this rod 35 acting as a lever about fulcrum38 and pulling the valve stem downwardly. This will pull the valve awayfrom the seat 12 admitting steam or the 43. In this normal posithe alarmwill, therefore like to the alarm device 43 which will sound to indicatean undesirable change in the water level in the boiler drum. Conversely,when the two weights with their connected rod 20 move upwardly, lever 32again moves, this time contacting with the right-hand boss 38 on lever35, the action of this lever being in this instance the same as before.It swings around fulcrum 36, moves valve stem 40 downwardly away fromseat 42, thus admitting steam to the alarm device or whistle 43.

It will be" apparent that when the water level in column 2 lowers so asto partly or completely uncover weight 22, spring 28 will be stretchedout in length by the addition of the unbuoyed weight, this beingdependent upon the portion of 22 that is uncovered. This increase inweight will operate to lower the rod 28 with associated weights 2| and22 with the result hereinbefore described. Similarly, when the waterraises above normal water level, weight 2| will be partly submerged. Theeffective weight of rod 20 with associated weights will be therebydecreased in dependence upon the amount of the portion of weight 2| thussubmerged which, in turn, will take a part of the weight or load fromspring 28. The result is that the weights 2| and 22 and associated rod2|! will rise upon attainment of this higher water level, with theresult herelnbefore described.

It is an important feature of applicant's invention that suitableadjustments may be made in the position of the weights without takingthe boiler out of service. If, for example, it is desired to carry thenormal water level in the boiler higher or lower due to changes inoperating conditions, the alarm mechanism may be readily adjusted tocompensate for the desired change, without taking the boiler out ofservice to reach the interior of the column. In the conventional type ofcolumn thisis not at all possible since the entire alarm mechanism isentirely supported inside the column.

This adjustment can obviously be accomplished by means of the adjustingscrew 29 and adjusting nut 3|| which may be reached by removal of thecap l8, and by means of member which may be raised or lowered by virtueof its threaded mounting in the cover 8. Thus it will be apparcut thatby adjusting the spring 28 the weights 2| and 22 may be raised orlowered and that the displacement of levers 32 and 35 effected by thisraising or lowering of the weights may be compensated for by verticaladjustment of the member 45 and thus of the valve seat 42. According topresent practice, valves are not permitted between the water colunm andthe boiler drum with the result that in order to adjust the conventionalhigh and low alarm mechanism, it is necessary to take the boiler out ofservice. It is an important feature of applicant's invention thatdesirable adjustments may be made without in any way disturbing theoperation of the boiler.

While I have shown and described one particularly preferred embodimentof my invention it is understood that the same may be varied withoutdeparting from the spirit of my invention and I wish to be limited onlyas set forth in the appended claims.

What I claim is:

1. In a liquid level indicator, 0. container for the liquid, a rodsuspended interiorly of. the container, a weight fixed to said rod abovethe normal liquid level in the container, 9. second weight fixed to saidrod below the normal liquid level in the container, a spring suspensionfor said rod aoeasia fixed to said rod below the normal liquid level inthe container, a spring suspension '!or said rod and associated weightslocated in a chamber separate from said container, and means actuated bysaid rod operable-to indicate when the level of the liquid reachespredetermined high or low limits.

3. In a liquid level indicator, a container for the liquid, a rodsuspended; vertically interiorly of the container, a weight fixedto'said rod above the normal liquid level in the container, a secondweight fixed to said rod below the normal liquid level in the container,means actuated by said rod operable to indicate when the level of theliquid reaches predetermined high or low limits, and means accessibleexteriorly' of the column to adjust the vertical and associated weights.I

4. In a liquid level indicator, a container for the liquid, 9. rodsuspended interiorly oi the container, a weight fixed to said rod abovethe normal liquid level in the container, a second weightfixed to saidrod below the normal liquid level in the containen a spring suspensionfor said rod and associated weights located in a chamber separate frombut inconstant communication with said container, and means to maintainsaid chamber at a relatively low temperature.

5. In a liquid level indicator, a column to receive the liquid, a rodsuspended interiorly of the column, a weight fixed to said rod, said rodand weight being movable vertically either upwardly or downwardly from anormal intermediate position upon changes in the liquid level in thecolumn, an alarm device communicating with the column, a valvecontrolling said communication, a lever actuated by the rod upon upwardor downward movement thereof away from said normal intermediate positionto open the valve, and means independent of the lever to support the rodand associated weight.

6. In a liquid level indicator, a column to receive the liquid, a rodsuspended interiorly of the column, a weight fixed to said rod above thenormal liquid level in the column, a second weight fixed to said rodbelow the normal liquid level in the column, said rod and weights movingvertically upon changes in the liquid level in the column, a. whistle, avalve controlling communication between said whistle and the column, alever actuated by the rod to operate the valve, and means independent ofthe lever to support the rod and associated weights.

7. In a liquid level indicator, a container to receive the liquid, a rodsuspended in the container, a weight fixed to the rod, and a spring forsuspending the rod and weight made of a copperberyllium alloy containingberyllium between two and'two and one half percent.

8. In a high and low alarm mechanism, a column, a whistle, a valve tocontrol communication between the whistle and the column, a levermovposition oi said rod able .to operate the valve and means swingablein two directions in a vertical plane to actuate the lever, said leverbeing provided with two depending portions, one of which is engaged bythe actuating means when it moves upwardly and the, other 01' which isengaged by the actuating means when it moves downwardly whereby thelever is moved in the same manner regardless of the direction ofmovement of the actuating means. 7

9. In a high and low alarm mechanism, a column to receive a liquid, arod suspended interiorly oi the column, a weight fixed to said rod abovethe normal liquid level in the column, a. second weight fixed to saidrod below the normal liquid level in the column, said rod and weightsmoving vertically upon changes in the liquid level in the column, analarm device, and means operating upon the vertical movement of the rodto a 'predetermined high or low the actuation of said alarm device.

10. In a liquid level indicator, an open top column to receive theliquid, a closure member for the top of the column, a rod suspendedinteriorly position for controlling of the column, a weight fixed to therod, a mem-- ber to support the rod and weight passing upwardly throughan opening in said closure member, a spring fixed to the upper portionoi. said member to support the member andthe rod with its associatedweight and means actuated by said rod operable to indicate ,when thelevel'of the liquid reaches predetermined high or low limits.

11. In a high and low alarm mechanism, a column to receive a liquid, arod suspended interiorly and centrally oi the column, a weight fixed atits center to the rod and located entirely above the normal liquid levelin the column, a second weight fixed at its center to the rod andlocated entirely below the normal liquid level in the column, said rodand weights moving vertically upon changes in the liquid level in thecolumn, and an alarm device operated in dependence upon vertical twodepending-portions, one of which is engaged by the actuating means whenit moves in one direction and the other of which is engaged by theactuating means when it moves in the other direction whereby the leveris moved in the same manner regardless of the direction of movement ofthe actuating means. a

13. In a high and low alarm mechanism, a container, an alarm, a levermovable to operate the alarm, means swingable in two directions toactuate the lever, said lever being provided with two dependingportions, one of which is engaged by the actuating means when it movesin one direction and the other oi which is engaged by the actuatingmeans when it moves in the other direction whereby the lever is moved inthe same manner regardless of the direction of movement 01 the actuatingmeans, and a rod movable vertically inthe container in response tochanges in the level 0! the liquid therein arranged to actuate saidactuating means.

CURTIS L. HOWBE.

